. >> president obama and first lady michelle will leave tomorrow for south africa. they'll attend a national memorial service for mandela on tuesday. >>> bay area churchgoers also honored the former south african president today. john shows us the celebration of his life and legacy at san francisco's glide memorial church. >> reporter: when san francisco's glide memorial church remembered nelson mandela at their services, the only thing missing was sadness. the mood was joyful as the children's choir honored the passing of the man who is being called the father of the nation. >> it's bigger than that. nelson mandela touched all of our lives regardless of where we were in the world. >> reporter: pastor sisal williams met him twice. he said mandela's power came from his ability to rise above the outrage of his imprisonment to become an irresistible force in the position of change. >> being in prison for 27 years, you hear me? 27 years. and then walking out of that prison as a new person completely. there's no doubt about it. he liberated the world in many ways. >> rep